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TOMOYO Linux Cross Reference
Linux/security/apparmor/lsm.c

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  1 /*
  2  * AppArmor security module
  3  *
  4  * This file contains AppArmor LSM hooks.
  5  *
  6  * Copyright (C) 1998-2008 Novell/SUSE
  7  * Copyright 2009-2010 Canonical Ltd.
  8  *
  9  * This program is free software; you can redistribute it and/or
 10  * modify it under the terms of the GNU General Public License as
 11  * published by the Free Software Foundation, version 2 of the
 12  * License.
 13  */
 14 
 15 #include <linux/security.h>
 16 #include <linux/moduleparam.h>
 17 #include <linux/mm.h>
 18 #include <linux/mman.h>
 19 #include <linux/mount.h>
 20 #include <linux/namei.h>
 21 #include <linux/ptrace.h>
 22 #include <linux/ctype.h>
 23 #include <linux/sysctl.h>
 24 #include <linux/audit.h>
 25 #include <linux/user_namespace.h>
 26 #include <net/sock.h>
 27 
 28 #include "include/apparmor.h"
 29 #include "include/apparmorfs.h"
 30 #include "include/audit.h"
 31 #include "include/capability.h"
 32 #include "include/context.h"
 33 #include "include/file.h"
 34 #include "include/ipc.h"
 35 #include "include/path.h"
 36 #include "include/policy.h"
 37 #include "include/procattr.h"
 38 
 39 /* Flag indicating whether initialization completed */
 40 int apparmor_initialized __initdata;
 41 
 42 /*
 43  * LSM hook functions
 44  */
 45 
 46 /*
 47  * free the associated aa_task_cxt and put its profiles
 48  */
 49 static void apparmor_cred_free(struct cred *cred)
 50 {
 51         aa_free_task_context(cred_cxt(cred));
 52         cred_cxt(cred) = NULL;
 53 }
 54 
 55 /*
 56  * allocate the apparmor part of blank credentials
 57  */
 58 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
 59 {
 60         /* freed by apparmor_cred_free */
 61         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
 62         if (!cxt)
 63                 return -ENOMEM;
 64 
 65         cred_cxt(cred) = cxt;
 66         return 0;
 67 }
 68 
 69 /*
 70  * prepare new aa_task_cxt for modification by prepare_cred block
 71  */
 72 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
 73                                  gfp_t gfp)
 74 {
 75         /* freed by apparmor_cred_free */
 76         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
 77         if (!cxt)
 78                 return -ENOMEM;
 79 
 80         aa_dup_task_context(cxt, cred_cxt(old));
 81         cred_cxt(new) = cxt;
 82         return 0;
 83 }
 84 
 85 /*
 86  * transfer the apparmor data to a blank set of creds
 87  */
 88 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
 89 {
 90         const struct aa_task_cxt *old_cxt = cred_cxt(old);
 91         struct aa_task_cxt *new_cxt = cred_cxt(new);
 92 
 93         aa_dup_task_context(new_cxt, old_cxt);
 94 }
 95 
 96 static int apparmor_ptrace_access_check(struct task_struct *child,
 97                                         unsigned int mode)
 98 {
 99         int error = cap_ptrace_access_check(child, mode);
100         if (error)
101                 return error;
102 
103         return aa_ptrace(current, child, mode);
104 }
105 
106 static int apparmor_ptrace_traceme(struct task_struct *parent)
107 {
108         int error = cap_ptrace_traceme(parent);
109         if (error)
110                 return error;
111 
112         return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
113 }
114 
115 /* Derived from security/commoncap.c:cap_capget */
116 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
117                            kernel_cap_t *inheritable, kernel_cap_t *permitted)
118 {
119         struct aa_profile *profile;
120         const struct cred *cred;
121 
122         rcu_read_lock();
123         cred = __task_cred(target);
124         profile = aa_cred_profile(cred);
125 
126         *effective = cred->cap_effective;
127         *inheritable = cred->cap_inheritable;
128         *permitted = cred->cap_permitted;
129 
130         if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
131                 *effective = cap_intersect(*effective, profile->caps.allow);
132                 *permitted = cap_intersect(*permitted, profile->caps.allow);
133         }
134         rcu_read_unlock();
135 
136         return 0;
137 }
138 
139 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
140                             int cap, int audit)
141 {
142         struct aa_profile *profile;
143         /* cap_capable returns 0 on success, else -EPERM */
144         int error = cap_capable(cred, ns, cap, audit);
145         if (!error) {
146                 profile = aa_cred_profile(cred);
147                 if (!unconfined(profile))
148                         error = aa_capable(profile, cap, audit);
149         }
150         return error;
151 }
152 
153 /**
154  * common_perm - basic common permission check wrapper fn for paths
155  * @op: operation being checked
156  * @path: path to check permission of  (NOT NULL)
157  * @mask: requested permissions mask
158  * @cond: conditional info for the permission request  (NOT NULL)
159  *
160  * Returns: %0 else error code if error or permission denied
161  */
162 static int common_perm(int op, struct path *path, u32 mask,
163                        struct path_cond *cond)
164 {
165         struct aa_profile *profile;
166         int error = 0;
167 
168         profile = __aa_current_profile();
169         if (!unconfined(profile))
170                 error = aa_path_perm(op, profile, path, 0, mask, cond);
171 
172         return error;
173 }
174 
175 /**
176  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
177  * @op: operation being checked
178  * @dir: directory of the dentry  (NOT NULL)
179  * @dentry: dentry to check  (NOT NULL)
180  * @mask: requested permissions mask
181  * @cond: conditional info for the permission request  (NOT NULL)
182  *
183  * Returns: %0 else error code if error or permission denied
184  */
185 static int common_perm_dir_dentry(int op, struct path *dir,
186                                   struct dentry *dentry, u32 mask,
187                                   struct path_cond *cond)
188 {
189         struct path path = { dir->mnt, dentry };
190 
191         return common_perm(op, &path, mask, cond);
192 }
193 
194 /**
195  * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
196  * @op: operation being checked
197  * @mnt: mount point of dentry (NOT NULL)
198  * @dentry: dentry to check  (NOT NULL)
199  * @mask: requested permissions mask
200  *
201  * Returns: %0 else error code if error or permission denied
202  */
203 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
204                                   struct dentry *dentry, u32 mask)
205 {
206         struct path path = { mnt, dentry };
207         struct path_cond cond = { dentry->d_inode->i_uid,
208                                   dentry->d_inode->i_mode
209         };
210 
211         return common_perm(op, &path, mask, &cond);
212 }
213 
214 /**
215  * common_perm_rm - common permission wrapper for operations doing rm
216  * @op: operation being checked
217  * @dir: directory that the dentry is in  (NOT NULL)
218  * @dentry: dentry being rm'd  (NOT NULL)
219  * @mask: requested permission mask
220  *
221  * Returns: %0 else error code if error or permission denied
222  */
223 static int common_perm_rm(int op, struct path *dir,
224                           struct dentry *dentry, u32 mask)
225 {
226         struct inode *inode = dentry->d_inode;
227         struct path_cond cond = { };
228 
229         if (!inode || !dir->mnt || !mediated_filesystem(inode))
230                 return 0;
231 
232         cond.uid = inode->i_uid;
233         cond.mode = inode->i_mode;
234 
235         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
236 }
237 
238 /**
239  * common_perm_create - common permission wrapper for operations doing create
240  * @op: operation being checked
241  * @dir: directory that dentry will be created in  (NOT NULL)
242  * @dentry: dentry to create   (NOT NULL)
243  * @mask: request permission mask
244  * @mode: created file mode
245  *
246  * Returns: %0 else error code if error or permission denied
247  */
248 static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
249                               u32 mask, umode_t mode)
250 {
251         struct path_cond cond = { current_fsuid(), mode };
252 
253         if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
254                 return 0;
255 
256         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
257 }
258 
259 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
260 {
261         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
262 }
263 
264 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
265                                umode_t mode)
266 {
267         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
268                                   S_IFDIR);
269 }
270 
271 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
272 {
273         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
274 }
275 
276 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
277                                umode_t mode, unsigned int dev)
278 {
279         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
280 }
281 
282 static int apparmor_path_truncate(struct path *path)
283 {
284         struct path_cond cond = { path->dentry->d_inode->i_uid,
285                                   path->dentry->d_inode->i_mode
286         };
287 
288         if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
289                 return 0;
290 
291         return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
292                            &cond);
293 }
294 
295 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
296                                  const char *old_name)
297 {
298         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
299                                   S_IFLNK);
300 }
301 
302 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
303                               struct dentry *new_dentry)
304 {
305         struct aa_profile *profile;
306         int error = 0;
307 
308         if (!mediated_filesystem(old_dentry->d_inode))
309                 return 0;
310 
311         profile = aa_current_profile();
312         if (!unconfined(profile))
313                 error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
314         return error;
315 }
316 
317 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
318                                 struct path *new_dir, struct dentry *new_dentry)
319 {
320         struct aa_profile *profile;
321         int error = 0;
322 
323         if (!mediated_filesystem(old_dentry->d_inode))
324                 return 0;
325 
326         profile = aa_current_profile();
327         if (!unconfined(profile)) {
328                 struct path old_path = { old_dir->mnt, old_dentry };
329                 struct path new_path = { new_dir->mnt, new_dentry };
330                 struct path_cond cond = { old_dentry->d_inode->i_uid,
331                                           old_dentry->d_inode->i_mode
332                 };
333 
334                 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
335                                      MAY_READ | AA_MAY_META_READ | MAY_WRITE |
336                                      AA_MAY_META_WRITE | AA_MAY_DELETE,
337                                      &cond);
338                 if (!error)
339                         error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
340                                              0, MAY_WRITE | AA_MAY_META_WRITE |
341                                              AA_MAY_CREATE, &cond);
342 
343         }
344         return error;
345 }
346 
347 static int apparmor_path_chmod(struct path *path, umode_t mode)
348 {
349         if (!mediated_filesystem(path->dentry->d_inode))
350                 return 0;
351 
352         return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
353 }
354 
355 static int apparmor_path_chown(struct path *path, kuid_t uid, kgid_t gid)
356 {
357         struct path_cond cond =  { path->dentry->d_inode->i_uid,
358                                    path->dentry->d_inode->i_mode
359         };
360 
361         if (!mediated_filesystem(path->dentry->d_inode))
362                 return 0;
363 
364         return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
365 }
366 
367 static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
368 {
369         if (!mediated_filesystem(dentry->d_inode))
370                 return 0;
371 
372         return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
373                                       AA_MAY_META_READ);
374 }
375 
376 static int apparmor_file_open(struct file *file, const struct cred *cred)
377 {
378         struct aa_file_cxt *fcxt = file->f_security;
379         struct aa_profile *profile;
380         int error = 0;
381 
382         if (!mediated_filesystem(file_inode(file)))
383                 return 0;
384 
385         /* If in exec, permission is handled by bprm hooks.
386          * Cache permissions granted by the previous exec check, with
387          * implicit read and executable mmap which are required to
388          * actually execute the image.
389          */
390         if (current->in_execve) {
391                 fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
392                 return 0;
393         }
394 
395         profile = aa_cred_profile(cred);
396         if (!unconfined(profile)) {
397                 struct inode *inode = file_inode(file);
398                 struct path_cond cond = { inode->i_uid, inode->i_mode };
399 
400                 error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
401                                      aa_map_file_to_perms(file), &cond);
402                 /* todo cache full allowed permissions set and state */
403                 fcxt->allow = aa_map_file_to_perms(file);
404         }
405 
406         return error;
407 }
408 
409 static int apparmor_file_alloc_security(struct file *file)
410 {
411         /* freed by apparmor_file_free_security */
412         file->f_security = aa_alloc_file_context(GFP_KERNEL);
413         if (!file->f_security)
414                 return -ENOMEM;
415         return 0;
416 
417 }
418 
419 static void apparmor_file_free_security(struct file *file)
420 {
421         struct aa_file_cxt *cxt = file->f_security;
422 
423         aa_free_file_context(cxt);
424 }
425 
426 static int common_file_perm(int op, struct file *file, u32 mask)
427 {
428         struct aa_file_cxt *fcxt = file->f_security;
429         struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
430         int error = 0;
431 
432         BUG_ON(!fprofile);
433 
434         if (!file->f_path.mnt ||
435             !mediated_filesystem(file_inode(file)))
436                 return 0;
437 
438         profile = __aa_current_profile();
439 
440         /* revalidate access, if task is unconfined, or the cached cred
441          * doesn't match or if the request is for more permissions than
442          * was granted.
443          *
444          * Note: the test for !unconfined(fprofile) is to handle file
445          *       delegation from unconfined tasks
446          */
447         if (!unconfined(profile) && !unconfined(fprofile) &&
448             ((fprofile != profile) || (mask & ~fcxt->allow)))
449                 error = aa_file_perm(op, profile, file, mask);
450 
451         return error;
452 }
453 
454 static int apparmor_file_permission(struct file *file, int mask)
455 {
456         return common_file_perm(OP_FPERM, file, mask);
457 }
458 
459 static int apparmor_file_lock(struct file *file, unsigned int cmd)
460 {
461         u32 mask = AA_MAY_LOCK;
462 
463         if (cmd == F_WRLCK)
464                 mask |= MAY_WRITE;
465 
466         return common_file_perm(OP_FLOCK, file, mask);
467 }
468 
469 static int common_mmap(int op, struct file *file, unsigned long prot,
470                        unsigned long flags)
471 {
472         int mask = 0;
473 
474         if (!file || !file->f_security)
475                 return 0;
476 
477         if (prot & PROT_READ)
478                 mask |= MAY_READ;
479         /*
480          * Private mappings don't require write perms since they don't
481          * write back to the files
482          */
483         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
484                 mask |= MAY_WRITE;
485         if (prot & PROT_EXEC)
486                 mask |= AA_EXEC_MMAP;
487 
488         return common_file_perm(op, file, mask);
489 }
490 
491 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
492                               unsigned long prot, unsigned long flags)
493 {
494         return common_mmap(OP_FMMAP, file, prot, flags);
495 }
496 
497 static int apparmor_file_mprotect(struct vm_area_struct *vma,
498                                   unsigned long reqprot, unsigned long prot)
499 {
500         return common_mmap(OP_FMPROT, vma->vm_file, prot,
501                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
502 }
503 
504 static int apparmor_getprocattr(struct task_struct *task, char *name,
505                                 char **value)
506 {
507         int error = -ENOENT;
508         /* released below */
509         const struct cred *cred = get_task_cred(task);
510         struct aa_task_cxt *cxt = cred_cxt(cred);
511         struct aa_profile *profile = NULL;
512 
513         if (strcmp(name, "current") == 0)
514                 profile = aa_get_newest_profile(cxt->profile);
515         else if (strcmp(name, "prev") == 0  && cxt->previous)
516                 profile = aa_get_newest_profile(cxt->previous);
517         else if (strcmp(name, "exec") == 0 && cxt->onexec)
518                 profile = aa_get_newest_profile(cxt->onexec);
519         else
520                 error = -EINVAL;
521 
522         if (profile)
523                 error = aa_getprocattr(profile, value);
524 
525         aa_put_profile(profile);
526         put_cred(cred);
527 
528         return error;
529 }
530 
531 static int apparmor_setprocattr(struct task_struct *task, char *name,
532                                 void *value, size_t size)
533 {
534         struct common_audit_data sa;
535         struct apparmor_audit_data aad = {0,};
536         char *command, *args = value;
537         size_t arg_size;
538         int error;
539 
540         if (size == 0)
541                 return -EINVAL;
542         /* args points to a PAGE_SIZE buffer, AppArmor requires that
543          * the buffer must be null terminated or have size <= PAGE_SIZE -1
544          * so that AppArmor can null terminate them
545          */
546         if (args[size - 1] != '\0') {
547                 if (size == PAGE_SIZE)
548                         return -EINVAL;
549                 args[size] = '\0';
550         }
551 
552         /* task can only write its own attributes */
553         if (current != task)
554                 return -EACCES;
555 
556         args = value;
557         args = strim(args);
558         command = strsep(&args, " ");
559         if (!args)
560                 return -EINVAL;
561         args = skip_spaces(args);
562         if (!*args)
563                 return -EINVAL;
564 
565         arg_size = size - (args - (char *) value);
566         if (strcmp(name, "current") == 0) {
567                 if (strcmp(command, "changehat") == 0) {
568                         error = aa_setprocattr_changehat(args, arg_size,
569                                                          !AA_DO_TEST);
570                 } else if (strcmp(command, "permhat") == 0) {
571                         error = aa_setprocattr_changehat(args, arg_size,
572                                                          AA_DO_TEST);
573                 } else if (strcmp(command, "changeprofile") == 0) {
574                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
575                                                              !AA_DO_TEST);
576                 } else if (strcmp(command, "permprofile") == 0) {
577                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
578                                                              AA_DO_TEST);
579                 } else
580                         goto fail;
581         } else if (strcmp(name, "exec") == 0) {
582                 if (strcmp(command, "exec") == 0)
583                         error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
584                                                              !AA_DO_TEST);
585                 else
586                         goto fail;
587         } else
588                 /* only support the "current" and "exec" process attributes */
589                 return -EINVAL;
590 
591         if (!error)
592                 error = size;
593         return error;
594 
595 fail:
596         sa.type = LSM_AUDIT_DATA_NONE;
597         sa.aad = &aad;
598         aad.profile = aa_current_profile();
599         aad.op = OP_SETPROCATTR;
600         aad.info = name;
601         aad.error = -EINVAL;
602         aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
603         return -EINVAL;
604 }
605 
606 static int apparmor_task_setrlimit(struct task_struct *task,
607                 unsigned int resource, struct rlimit *new_rlim)
608 {
609         struct aa_profile *profile = __aa_current_profile();
610         int error = 0;
611 
612         if (!unconfined(profile))
613                 error = aa_task_setrlimit(profile, task, resource, new_rlim);
614 
615         return error;
616 }
617 
618 static struct security_operations apparmor_ops = {
619         .name =                         "apparmor",
620 
621         .ptrace_access_check =          apparmor_ptrace_access_check,
622         .ptrace_traceme =               apparmor_ptrace_traceme,
623         .capget =                       apparmor_capget,
624         .capable =                      apparmor_capable,
625 
626         .path_link =                    apparmor_path_link,
627         .path_unlink =                  apparmor_path_unlink,
628         .path_symlink =                 apparmor_path_symlink,
629         .path_mkdir =                   apparmor_path_mkdir,
630         .path_rmdir =                   apparmor_path_rmdir,
631         .path_mknod =                   apparmor_path_mknod,
632         .path_rename =                  apparmor_path_rename,
633         .path_chmod =                   apparmor_path_chmod,
634         .path_chown =                   apparmor_path_chown,
635         .path_truncate =                apparmor_path_truncate,
636         .inode_getattr =                apparmor_inode_getattr,
637 
638         .file_open =                    apparmor_file_open,
639         .file_permission =              apparmor_file_permission,
640         .file_alloc_security =          apparmor_file_alloc_security,
641         .file_free_security =           apparmor_file_free_security,
642         .mmap_file =                    apparmor_mmap_file,
643         .mmap_addr =                    cap_mmap_addr,
644         .file_mprotect =                apparmor_file_mprotect,
645         .file_lock =                    apparmor_file_lock,
646 
647         .getprocattr =                  apparmor_getprocattr,
648         .setprocattr =                  apparmor_setprocattr,
649 
650         .cred_alloc_blank =             apparmor_cred_alloc_blank,
651         .cred_free =                    apparmor_cred_free,
652         .cred_prepare =                 apparmor_cred_prepare,
653         .cred_transfer =                apparmor_cred_transfer,
654 
655         .bprm_set_creds =               apparmor_bprm_set_creds,
656         .bprm_committing_creds =        apparmor_bprm_committing_creds,
657         .bprm_committed_creds =         apparmor_bprm_committed_creds,
658         .bprm_secureexec =              apparmor_bprm_secureexec,
659 
660         .task_setrlimit =               apparmor_task_setrlimit,
661 };
662 
663 /*
664  * AppArmor sysfs module parameters
665  */
666 
667 static int param_set_aabool(const char *val, const struct kernel_param *kp);
668 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
669 #define param_check_aabool param_check_bool
670 static struct kernel_param_ops param_ops_aabool = {
671         .flags = KERNEL_PARAM_FL_NOARG,
672         .set = param_set_aabool,
673         .get = param_get_aabool
674 };
675 
676 static int param_set_aauint(const char *val, const struct kernel_param *kp);
677 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
678 #define param_check_aauint param_check_uint
679 static struct kernel_param_ops param_ops_aauint = {
680         .set = param_set_aauint,
681         .get = param_get_aauint
682 };
683 
684 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
685 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
686 #define param_check_aalockpolicy param_check_bool
687 static struct kernel_param_ops param_ops_aalockpolicy = {
688         .flags = KERNEL_PARAM_FL_NOARG,
689         .set = param_set_aalockpolicy,
690         .get = param_get_aalockpolicy
691 };
692 
693 static int param_set_audit(const char *val, struct kernel_param *kp);
694 static int param_get_audit(char *buffer, struct kernel_param *kp);
695 
696 static int param_set_mode(const char *val, struct kernel_param *kp);
697 static int param_get_mode(char *buffer, struct kernel_param *kp);
698 
699 /* Flag values, also controllable via /sys/module/apparmor/parameters
700  * We define special types as we want to do additional mediation.
701  */
702 
703 /* AppArmor global enforcement switch - complain, enforce, kill */
704 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
705 module_param_call(mode, param_set_mode, param_get_mode,
706                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
707 
708 /* Debug mode */
709 bool aa_g_debug;
710 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
711 
712 /* Audit mode */
713 enum audit_mode aa_g_audit;
714 module_param_call(audit, param_set_audit, param_get_audit,
715                   &aa_g_audit, S_IRUSR | S_IWUSR);
716 
717 /* Determines if audit header is included in audited messages.  This
718  * provides more context if the audit daemon is not running
719  */
720 bool aa_g_audit_header = 1;
721 module_param_named(audit_header, aa_g_audit_header, aabool,
722                    S_IRUSR | S_IWUSR);
723 
724 /* lock out loading/removal of policy
725  * TODO: add in at boot loading of policy, which is the only way to
726  *       load policy, if lock_policy is set
727  */
728 bool aa_g_lock_policy;
729 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
730                    S_IRUSR | S_IWUSR);
731 
732 /* Syscall logging mode */
733 bool aa_g_logsyscall;
734 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
735 
736 /* Maximum pathname length before accesses will start getting rejected */
737 unsigned int aa_g_path_max = 2 * PATH_MAX;
738 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
739 
740 /* Determines how paranoid loading of policy is and how much verification
741  * on the loaded policy is done.
742  */
743 bool aa_g_paranoid_load = 1;
744 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
745                    S_IRUSR | S_IWUSR);
746 
747 /* Boot time disable flag */
748 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
749 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
750 
751 static int __init apparmor_enabled_setup(char *str)
752 {
753         unsigned long enabled;
754         int error = strict_strtoul(str, 0, &enabled);
755         if (!error)
756                 apparmor_enabled = enabled ? 1 : 0;
757         return 1;
758 }
759 
760 __setup("apparmor=", apparmor_enabled_setup);
761 
762 /* set global flag turning off the ability to load policy */
763 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
764 {
765         if (!capable(CAP_MAC_ADMIN))
766                 return -EPERM;
767         if (aa_g_lock_policy)
768                 return -EACCES;
769         return param_set_bool(val, kp);
770 }
771 
772 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
773 {
774         if (!capable(CAP_MAC_ADMIN))
775                 return -EPERM;
776         return param_get_bool(buffer, kp);
777 }
778 
779 static int param_set_aabool(const char *val, const struct kernel_param *kp)
780 {
781         if (!capable(CAP_MAC_ADMIN))
782                 return -EPERM;
783         return param_set_bool(val, kp);
784 }
785 
786 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
787 {
788         if (!capable(CAP_MAC_ADMIN))
789                 return -EPERM;
790         return param_get_bool(buffer, kp);
791 }
792 
793 static int param_set_aauint(const char *val, const struct kernel_param *kp)
794 {
795         if (!capable(CAP_MAC_ADMIN))
796                 return -EPERM;
797         return param_set_uint(val, kp);
798 }
799 
800 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
801 {
802         if (!capable(CAP_MAC_ADMIN))
803                 return -EPERM;
804         return param_get_uint(buffer, kp);
805 }
806 
807 static int param_get_audit(char *buffer, struct kernel_param *kp)
808 {
809         if (!capable(CAP_MAC_ADMIN))
810                 return -EPERM;
811 
812         if (!apparmor_enabled)
813                 return -EINVAL;
814 
815         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
816 }
817 
818 static int param_set_audit(const char *val, struct kernel_param *kp)
819 {
820         int i;
821         if (!capable(CAP_MAC_ADMIN))
822                 return -EPERM;
823 
824         if (!apparmor_enabled)
825                 return -EINVAL;
826 
827         if (!val)
828                 return -EINVAL;
829 
830         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
831                 if (strcmp(val, audit_mode_names[i]) == 0) {
832                         aa_g_audit = i;
833                         return 0;
834                 }
835         }
836 
837         return -EINVAL;
838 }
839 
840 static int param_get_mode(char *buffer, struct kernel_param *kp)
841 {
842         if (!capable(CAP_MAC_ADMIN))
843                 return -EPERM;
844 
845         if (!apparmor_enabled)
846                 return -EINVAL;
847 
848         return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
849 }
850 
851 static int param_set_mode(const char *val, struct kernel_param *kp)
852 {
853         int i;
854         if (!capable(CAP_MAC_ADMIN))
855                 return -EPERM;
856 
857         if (!apparmor_enabled)
858                 return -EINVAL;
859 
860         if (!val)
861                 return -EINVAL;
862 
863         for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
864                 if (strcmp(val, aa_profile_mode_names[i]) == 0) {
865                         aa_g_profile_mode = i;
866                         return 0;
867                 }
868         }
869 
870         return -EINVAL;
871 }
872 
873 /*
874  * AppArmor init functions
875  */
876 
877 /**
878  * set_init_cxt - set a task context and profile on the first task.
879  *
880  * TODO: allow setting an alternate profile than unconfined
881  */
882 static int __init set_init_cxt(void)
883 {
884         struct cred *cred = (struct cred *)current->real_cred;
885         struct aa_task_cxt *cxt;
886 
887         cxt = aa_alloc_task_context(GFP_KERNEL);
888         if (!cxt)
889                 return -ENOMEM;
890 
891         cxt->profile = aa_get_profile(root_ns->unconfined);
892         cred_cxt(cred) = cxt;
893 
894         return 0;
895 }
896 
897 static int __init apparmor_init(void)
898 {
899         int error;
900 
901         if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
902                 aa_info_message("AppArmor disabled by boot time parameter");
903                 apparmor_enabled = 0;
904                 return 0;
905         }
906 
907         error = aa_alloc_root_ns();
908         if (error) {
909                 AA_ERROR("Unable to allocate default profile namespace\n");
910                 goto alloc_out;
911         }
912 
913         error = set_init_cxt();
914         if (error) {
915                 AA_ERROR("Failed to set context on init task\n");
916                 goto register_security_out;
917         }
918 
919         error = register_security(&apparmor_ops);
920         if (error) {
921                 struct cred *cred = (struct cred *)current->real_cred;
922                 aa_free_task_context(cred_cxt(cred));
923                 cred_cxt(cred) = NULL;
924                 AA_ERROR("Unable to register AppArmor\n");
925                 goto register_security_out;
926         }
927 
928         /* Report that AppArmor successfully initialized */
929         apparmor_initialized = 1;
930         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
931                 aa_info_message("AppArmor initialized: complain mode enabled");
932         else if (aa_g_profile_mode == APPARMOR_KILL)
933                 aa_info_message("AppArmor initialized: kill mode enabled");
934         else
935                 aa_info_message("AppArmor initialized");
936 
937         return error;
938 
939 register_security_out:
940         aa_free_root_ns();
941 
942 alloc_out:
943         aa_destroy_aafs();
944 
945         apparmor_enabled = 0;
946         return error;
947 }
948 
949 security_initcall(apparmor_init);
950 

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